326555981 has 2 divisors, whose sum is σ = 326555982. Its totient is φ = 326555980.

The previous prime is 326555963. The next prime is 326556017. The reversal of 326555981 is 189555623.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 309408100 + 17147881 = 17590^2 + 4141^2 .

It is an emirp because it is prime and its reverse (189555623) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 326555981 - 2¹⁸ = 326293837 is a prime.

It is a super-2 number, since 2×326555981² = 213277617453744722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (326555381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163277990 + 163277991.

It is an arithmetic number, because the mean of its divisors is an integer number (163277991).

Almost surely, 2^326555981 is an apocalyptic number.

It is an amenable number.

326555981 is a deficient number, since it is larger than the sum of its proper divisors (1).

326555981 is an equidigital number, since it uses as much as digits as its factorization.

326555981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 324000, while the sum is 44.

The square root of 326555981 is about 18070.8599961374. The cubic root of 326555981 is about 688.6299081902.

The spelling of 326555981 in words is "three hundred twenty-six million, five hundred fifty-five thousand, nine hundred eighty-one".